Telecommunications apparatus and methods

ABSTRACT

A network infrastructure equipment establishes a configuration of radio resources within a second frequency band for use by a terminal device for communications with network infrastructure equipment based on a first radio access technology and communicates an indication of that to the terminal device. The terminal device establishes a configuration of radio resources for use by the terminal device for communications based on a second radio access technology and determines if there is any overlap in radio resources configured for use by two different radio access technologies, and if so communicates an indication of that to the network infrastructure equipment. In response the network infrastructure equipment establishes a replacement configuration of radio resources for communications with the terminal device based on the first radio access technology that avoids the radio resources indicated as subject to overlap, and transmits an indication of the replacement configuration to the terminal device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of Ser. No. 15/504,145 filed Feb. 15,2017, which is a National Stage Entry of International PatentApplication No. PCT/EP2015/069742 filed Aug. 28, 2015, and claimspriority to European Patent Application 14 186 237.5, filed in theEuropean Patent Office on Sep. 24, 2014, the entire contents of each ofwhich being incorporated herein by reference.

BACKGROUND Field

The present disclosure relates to mobile communications networks andmethods for communicating data using mobile communications networks,infrastructure equipment for mobile communications networks,communications devices for communicating data via mobile communicationsnetworks and methods of communicating via mobile communicationsnetworks.

Description of Related Art

The “background” description provided herein is for the purpose ofgenerally presenting the context of the disclosure. Work of thepresently named inventors, to the extent it is described in thisbackground section, as well as aspects of the description which may nototherwise qualify as prior art at the time of filing, are neitherexpressly or impliedly admitted as prior art against the presentinvention.

It is well known in the field of wireless telecommunications for regionsof the radio spectrum to be assigned to different mobile networkoperators (MNO) for their exclusive use through a license. A licensetypically grants an MNO exclusive use over a number of years of apredefined portion of the radio frequency spectrum in which to deploy amobile communications network (e.g. GSM, WCDMA/HSPA, LTE/LTE-A). As aresult of this approach, an operator has guarantees of no other radioservices interfering with the radio resources that have been assigned tothe operator, and within the limitations of the license conditions ithas exclusive control over what radio technology it deploys in thenetwork. Consequently, a wireless telecommunications system that isprimarily designed to operate using radio resources that have beenlicensed for exclusive use by the wireless telecommunications system canoperate with a degree of centralised control and coordination to helpmake most efficient use of the available radio resources. Such awireless telecommunication system also manages all the interferenceinternally, based on standard specifications, since the license grantsit good immunity from external interference sources. Coexistence ofdifferent devices deployed on an MNO's licensed band is managed throughconformance to relevant radio standards. Licensed spectrum is todayusually assigned to operators via government-organised auctions, butso-called “beauty contests” continue also to be in use.

It is also well known in the field of wireless telecommunications forregions of the available radio spectrum to remain unlicensed. Unlicensed(license exempt) radio spectrum may, at least to some extent, be freelyused by a number of different technologies, such as Wi-Fi and Bluetoothand other non-3GPP radio access technologies. Operating parameters fordevices using unlicensed spectrum bands are typically stipulated bytechnical regulatory requirements such as e.g. the FCC Part 15 rule for2.4 GHz ISM band. Coexistence of different devices deployed onunlicensed band, due to the lack of centralised coordination andcontrol, is usually based on such technical rules and various politenessprotocols.

The use of wireless telecommunications system technologies designed foroperation on licensed radio spectrum, such as LTE, is becoming more andmore prevalent, both in terms of increasing take-up of established usesfor wireless telecommunications technologies, and also the introductionof new uses, e.g., in the developing field of machine-typecommunications (MTC). In order to help provide more bandwidth to supportthis increased use of wireless telecommunications technologies, it hasrecently been proposed to use unlicensed radio spectrum resources tosupport operations on licensed radio spectrum.

However, in contrast to licensed spectrum, unlicensed spectrum can beshared and used among different technologies, or different networksusing the same technology, without any coordinated/centralised control,for example to provide protection against interference. As a consequenceof this, the use of wireless technologies in unlicensed spectrum can besubject to unpredictable interference and has no guarantees of spectrumresources, i.e. the radio connection takes place on a best effort basis.This means that wireless network technologies, such as LTE, which aregenerally designed to operate using licensed radio resources, requiremodified approaches to allow them to efficiently use unlicensed radioresources, and in particular to co-exist reliably and fairly with otherradio access technologies that may be simultaneously operating in theunlicensed spectrum band.

Therefore, deploying a mobile radio access technology system primarilydesigned to operate in licensed spectrum bands (i.e. having exclusiveaccess to, and hence a level of control over, the relevant radioresources) in a manner which is required by operation in unlicensedspectrum bands (i.e. without having exclusive access to at least some ofthe relevant radio resources), gives rise to new technical challenges.

SUMMARY

According to one aspect of the present disclosure, there is provided amethod of operating a terminal device in a wireless telecommunicationssystem for communicating with network infrastructure equipment inaccordance with a first radio access technology on a primary cellsupporting a primary component carrier on radio resources within a firstfrequency band and a secondary cell supporting a secondary componentcarrier on radio resources within a second frequency band, wherein theterminal device is also operable to use radio resources within thesecond frequency band for communicating in accordance with a secondradio access technology, wherein the method comprises: receiving fromthe network infrastructure equipment an indication of a configuration ofradio resources within the second frequency band for use by the terminaldevice for communications with the network infrastructure equipment inaccordance with the first radio access technology; establishing aconfiguration of radio resources within the second frequency band foruse by the terminal device for communications in accordance with thesecond radio access technology; determining if there is an overlap inthe radio resources configured for use by the terminal device forcommunications in accordance with the first radio access technology andthe radio resources configured for use by the terminal device forcommunications in accordance with the second radio access technology,and if so, transmitting signaling to the network infrastructureequipment to indicate there is an overlap.

According to another aspect of the present disclosure, there is provideda terminal device for use in a wireless telecommunications system forcommunicating with network infrastructure equipment in accordance with afirst radio access technology on a primary cell supporting a primarycomponent carrier on radio resources within a first frequency band and asecondary cell supporting a secondary component carrier on radioresources within a second frequency band, wherein the terminal device isfurther operable to use radio resources within the second frequency bandfor communicating in accordance with a second radio access technology,and wherein the terminal device comprises a controller unit and atransceiver unit configured to operate together to: receive from thenetwork infrastructure equipment an indication of a configuration ofradio resources within the second frequency band for use by the terminaldevice for communications with the network infrastructure equipment inaccordance with the first radio access technology; establish aconfiguration of radio resources within the second frequency band foruse by the terminal device for communications in accordance with thesecond radio access technology; determine if there is an overlap in theradio resources configured for use by the terminal device forcommunications in accordance with the first radio access technology andthe radio resources configured for use by the terminal device forcommunications in accordance with the second radio access technology,and if so, transmit signaling to the network infrastructure equipment toindicate there is an overlap.

According to another aspect of the present disclosure, there is providedcircuitry for a terminal device in a wireless telecommunications systemfor communicating with network infrastructure equipment in accordancewith a first radio access technology on a primary cell supporting aprimary component carrier on radio resources within a first frequencyband and a secondary cell supporting a secondary component carrier onradio resources within a second frequency band, wherein the terminaldevice is further operable to use radio resources within the secondfrequency band for communicating in accordance with a second radioaccess technology, wherein the circuitry comprises a controller elementand a transceiver element configured to operate together to: receivefrom the network infrastructure equipment an indication of aconfiguration of radio resources within the second frequency band foruse by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology; establish a configuration of radio resources within thesecond frequency band for use by the terminal device for communicationsin accordance with the second radio access technology; determine ifthere is an overlap in the radio resources configured for use by theterminal device for communications in accordance with the first radioaccess technology and the radio resources configured for use by theterminal device for communications in accordance with the second radioaccess technology, and if so, transmit signaling to the networkinfrastructure equipment to indicate there is an overlap.

According to another aspect of the present disclosure, there is provideda method of operating network infrastructure equipment in a wirelesstelecommunications system for communicating with a terminal device inaccordance with a first radio access technology on a primary cellsupporting a primary component carrier on radio resources within a firstfrequency band and a secondary cell supporting a secondary componentcarder on radio resources within a second frequency band, wherein theterminal device is further operable to use radio resources within thesecond frequency band for communicating in accordance with a secondradio access technology, wherein the method comprises: establishing aconfiguration of radio resources within the second frequency band foruse by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology: transmitting to the terminal device an indication of theconfiguration of radio resources within the second frequency band foruse by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology; receiving from the terminal device an indication of anoverlap in the radio resources configured for use by the terminal devicefor communications in accordance with the first radio access technologyand radio resources which the terminal devoice has established areneeded for use by the terminal device for communications in accordancewith the second radio access technology; establishing a replacementconfiguration of radio resources within the second frequency band foruse by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology, wherein the replacement configuration is selected to avoidradio resources in respect of which the overlap is indicated; andtransmitting to the terminal device an indication of the replacementconfiguration of radio resources within the second frequency band foruse by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology.

According to another aspect of the present disclosure, there is providednetwork infrastructure equipment for use in a wirelesstelecommunications system for communicating with a terminal device inaccordance with a first radio access technology on a primary cellsupporting a primary component carrier on radio resources within a firstfrequency band and a secondary cell supporting a secondary componentcarrier on radio resources within a second frequency band, wherein theterminal device is further operable to use radio resources within thesecond frequency band for communicating in accordance with a secondradio access technology, and wherein the network infrastructureequipment comprises a controller unit and a transceiver unit configuredto operate together to: establish a configuration of radio resourceswithin the second frequency band for use by the terminal device forcommunications with the network infrastructure equipment in accordancewith the first radio access technology; transmit to the terminal devicean indication of the configuration of radio resources within the secondfrequency band for use by the terminal device for communications withthe network infrastructure equipment in accordance with the first radioaccess technology; receive from the terminal device an indication of anoverlap in the radio resources configured for use by the terminal devicefor communications in accordance with the first radio access technologyand radio resources which the terminal devoice has established areneeded for use by the terminal device for communications in accordancewith the second radio access technology; establish a replacementconfiguration of radio resources within the second frequency band foruse by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology, wherein the replacement configuration is selected to avoidradio resources in respect of which the overlap is indicated; andtransmit to the terminal device an indication of the replacementconfiguration of radio resources within the second frequency band foruse by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology.

According to another aspect of the present disclosure, there is providedcircuitry for network infrastructure equipment for use in a wirelesstelecommunications system for communicating with a terminal device inaccordance with a first radio access technology on a primary cellsupporting a primary component carrier on radio resources within a firstfrequency band and a secondary cell supporting a secondary componentcarrier on radio resources within a second frequency band, wherein theterminal device is further operable to use radio resources within thesecond frequency band for communicating in accordance with a secondradio access technology, and wherein the circuitry comprises acontroller element and a transceiver element configured to operatetogether to: establish a configuration of radio resources within thesecond frequency band for use by the terminal device for communicationswith the network infrastructure equipment in accordance with the firstradio access technology; transmit to the terminal device an indicationof the configuration of radio resources within the second frequency bandfor use by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology; receive from the terminal device an indication of an overlapin the radio resources configured for use by the terminal device forcommunications in accordance with the first radio access technology andradio resources which the terminal devoice has established are neededfor use by the terminal device for communications in accordance with thesecond radio access technology; establish a replacement configuration ofradio resources within the second frequency band for use by the terminaldevice for communications with the network infrastructure equipment inaccordance with the first radio access technology, wherein thereplacement configuration is selected to avoid radio resources inrespect of which the overlap is indicated; and transmit to the terminaldevice an indication of the replacement configuration of radio resourceswithin the second frequency band for use by the terminal device forcommunications with the network infrastructure equipment in accordancewith the first radio access technology.

Further respective aspects and features are defined by the appendedclaims.

The foregoing paragraphs have been provided by way of generalintroduction, and are not intended to limit the scope of the followingclaims. The described embodiments, together with further advantages,will be best understood by reference to the following detaileddescription taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the disclosure and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings wherein likereference numerals designate identical or corresponding parts throughoutthe several views, and wherein:

FIG. 1 provides a schematic diagram illustrating an example of a mobiletelecommunication system;

FIG. 2 provides a schematic diagram illustrating a LTE radio frame;

FIG. 3 provides a schematic diagram illustrating an example of a LTEdownlink radio subframe;

FIG. 4 schematically represents a wireless telecommunications systemaccording to an embodiment of the disclosure; and

FIG. 5 is a signaling ladder diagram representing some operating aspectsof a base station and a terminal device in accordance with someembodiments of the disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 provides a schematic diagram illustrating some basicfunctionality of a mobile telecommunications network/system 100operating in accordance with LTE principles and which may be adapted toimplement embodiments of the disclosure as described further below.Various elements of FIG. 1 and their respective modes of operation arewell-known and defined in the relevant standards administered by the3GPP® body, and also described in many books on the subject, forexample, Holma H. and Toskala A [1]. It will be appreciated thatoperational aspects of the telecommunications network which are notspecifically described below may be implemented in accordance with anyknown techniques, for example according to the relevant standards.

The network 100 includes a plurality of base stations 101 connected to acore network 102. Each base station provides a coverage area 103 (i.e. acell) within which data can be communicated to and from terminal devices104. Data is transmitted from base stations 101 to terminal devices 104within their respective coverage areas 103 via a radio downlink. Data istransmitted from terminal devices 104 to the base stations 101 via aradio uplink. The uplink and downlink communications are made usingradio resources that are licensed for use by the operator of the network100. The core network 102 routes data to and from the terminal devices104 via the respective base stations 101 and provides functions such asauthentication, mobility management, charging and so on. Terminaldevices may also be referred to as mobile stations, user equipment (UE),user terminal, mobile radio, and so forth. Base stations may also bereferred to as transceiver stations/nodeBs/e-nodeBs, and so forth.

Mobile telecommunications systems such as those arranged in accordancewith the 3GPP defined Long Term Evolution (LTE) architecture use anorthogonal frequency division modulation (OFDM) based interface for theradio downlink (so-called OFDMA) and a single carrier frequency divisionmultiple access scheme (SC-FDMA) on the radio uplink. FIG. 2 shows aschematic diagram illustrating an OFDM based LTE downlink radio frame201. The LTE downlink radio frame is transmitted from a LTE base station(known as an enhanced Node B) and lasts 10 ms. The downlink radio framecomprises ten subframes, each subframe lasting 1 ms. A primarysynchronisation signal (PSS) and a secondary synchronisation signal(SSS) are transmitted in the first and sixth subframes of the LTE frame.A physical broadcast channel (PBCH) is transmitted in the first subframeof the LTE frame.

FIG. 3 is a schematic diagram of a grid which illustrates the structureof an example conventional downlink LTE subframe. The subframe comprisesa predetermined number of symbols which are transmitted over a 1 msperiod. Each symbol comprises a predetermined number of orthogonalsubcarriers distributed across the bandwidth of the downlink radiocarrier.

The example subframe shown in FIG. 3 comprises 14 symbols and 1200subcarriers spread across a 20 MHz bandwidth licensed for use by theoperator of the network 100, and this example is the first subframe in aframe (hence it contains PBCH). The smallest allocation of physicalresource for transmission in LTE is a resource block comprising twelvesubcarriers transmitted over one subframe. For clarity, in FIG. 3, eachindividual resource element is not shown, instead each individual box inthe subframe grid corresponds to twelve subcarriers transmitted on onesymbol.

FIG. 3 shows in hatching resource allocations for four LTE terminals340, 341, 342, 343. For example, the resource allocation 342 for a firstLTE terminal (UE 1) extends over five blocks of twelve subcarriers (i.e.60 subcarriers), the resource allocation 343 for a second LTE terminal(UE2) extends over six blocks of twelve subcarriers (i.e. 72subcarriers), and so on.

Control channel data can be transmitted in a control region 300(indicated by dotted-shading in FIG. 3) of the subframe comprising thefirst “n” symbols of the subframe where “n” can vary between one andthree symbols for channel bandwidths of 3 MHz or greater and where “n”can vary between two and four symbols for a channel bandwidth of 1.4MHz. For the sake of providing a concrete example, the followingdescription relates to host carriers with a channel bandwidth of 3 MHzor greater so the maximum value of “n” will be 3 (as in the example ofFIG. 3). The data transmitted in the control region 300 includes datatransmitted on the physical downlink control channel (PDCCH), thephysical control format indicator channel (PCFICH) and the physical HARQindicator channel (PHICH). These channels transmit physical layercontrol information. Control channel data can also or alternatively betransmitted in a second region of the subframe comprising a number ofsubcarriers for a time substantially equivalent to the duration of thesubframe, or substantially equivalent to the duration of the subframeremaining after the “n” symbols. The data transmitted in this secondregion is transmitted on the enhanced physical downlink control channel(EPDCCH). This channel transmits physical layer control informationwhich may be in addition to that transmitted on other physical layercontrol channels.

PDCCH and EPDCCH contain control data indicating which subcarriers ofthe subframe have been allocated to specific terminals (or all terminalsor subset of terminals). This may be referred to as physical-layercontrol signaling/data. Thus, the PDCCH and/or EPDCCH data transmittedin the control region 300 of the subframe shown in FIG. 3 would indicatethat UE1 has been allocated the block of resources identified byreference numeral 342, that UE2 has been allocated the block ofresources identified by reference numeral 343, and so on.

PCFICH contains control data indicating the size of the control region(i.e. between one and three symbols for channel bandwidths of 3 MHz orgreater and between two and four symbols for channel bandwidths of 1.4MHz).

PHICH contains HARQ (Hybrid Automatic Request) data indicating whetheror not previously transmitted uplink data has been successfully receivedby the network.

Symbols in a central band 310 of the time-frequency resource grid areused for the transmission of information including the primarysynchronisation signal (PSS), the secondary synchronisation signal (SSS)and the physical broadcast channel (PBCH). This central band 310 istypically 72 subcarriers wide (corresponding to a transmission bandwidthof 1.08 MHz). The PSS and SSS are synchronisation signals that oncedetected allow a LTE terminal device to achieve frame synchronisationand determine the physical layer cell identity of the enhanced Node Btransmitting the downlink signal. The PBCH carries information about thecell, comprising a master information block (MIB) that includesparameters that LTE terminals use to properly access the cell. Datatransmitted to terminals on the physical downlink shared channel(PDSCH), which may also be referred to as a downlink data channel, canbe transmitted in other resource elements of the subframe. In generalPDSCH conveys a combination of user-plane data and non-physical layercontrol-plane data (such as Radio Resource Control (RRC) and Non AccessStratum (NAS) signaling). The user-plane data and non-physical layercontrol-plane data conveyed on PDSCH may be referred to as higher layerdata (i.e. data associated with a layer higher than the physical layer).

FIG. 3 also shows a region of PDSCH containing system information andextending over a bandwidth of R344. A conventional LTE subframe willalso include reference signals which are not shown in FIG. 3 in theinterests of clarity.

The number of subcarriers in a LTE channel can vary depending on theconfiguration of the transmission network. Typically this variation isfrom 72 sub carriers contained within a 1.4 MHz channel bandwidth to1200 subcarriers contained within a 20 MHz channel bandwidth (asschematically shown in FIG. 3). As is known in the art, data transmittedon the PDCCH, PCFICH and PHICH is typically distributed on thesubcarriers across the entire bandwidth of the subframe to provide forfrequency diversity.

The communications between the base stations 101 and the terminaldevices 104 are conventionally made using radio resources that have beenlicensed for exclusive use by the operator of the network 100. Theselicensed radio resources will be only a portion of the overall radiospectrum. Other devices within the environment of the network 100 may bewirelessly communicating using other radio resources. For example, adifferent operator's network may be operating within the samegeographical region using different radio resources that have beenlicensed for use by the different operator. Other devices may beoperating using other radio resources in an unlicensed radio spectrumband, for example using Wi-Fi or Bluetooth technologies.

As noted above, it has been proposed that a wireless telecommunicationsnetwork using radio resources in a licensed portion of the radiospectrum might be supported by using radio resources in an unlicensedportion of the radio spectrum (i.e. a portion of the radio spectrum overwhich the wireless telecommunications network does not have exclusiveaccess, but rather which is shared by other access technologies and/orother wireless telecommunications networks). In particular, it has beenproposed that carrier aggregation based techniques may be used to allowlicense-exempt radio resources to be used in conjunction with licensedradio resources.

In essence, carrier aggregation allows for communications between a basestation and a terminal device to be made using more than one carrier.This can increase the maximum data rate that may be achieved between abase station and a terminal device as compared to when using only onecarrier and can help enable more efficient and productive use offragmented spectrum. Individual carriers that are aggregated arecommonly referred to as component carriers (or sometimes simplycomponents). In the context of LTE, carrier aggregation was introducedin Release 10 of the standard. In accordance with the current standardsfor carrier aggregation in an LTE-based system, up to five componentcarriers can be aggregated for each of downlink and uplink. Thecomponent carriers are not required to be contiguous with one anotherand can have a system bandwidth corresponding to any of the LTE-definedvalues (1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz and 20 MHz), therebyallowing a total bandwidth of up to 100 MHz. Of course it will beappreciated this is just one example of a specific carrier aggregationimplementation and other implementations may allow for different numbersof component carriers and/or bandwidths.

Further information on the operation of carrier aggregation in thecontext of LTE-based wireless telecommunications systems can be found inthe relevant standards documents, such as ETSI TS 136 211 V11.5.0 (2014Jan.)/3GPP TS 36.211 version 11.5.0 Release 11 [2], ETSI TS 136 212V11.4.0 (2014 Jan.)/3GPP TS 36.212 version 11.4.0 Release 11 [3]; ETSITS 136 213 V11.6.0 (2014 Mar.)/3GPP TS 36.213 version 11.6.0 Release 11[4]; ETSI TS 136 321 V11.5.0 (2014 Mar.)/3GPP TS 36.321 version 11.5.0Release 11 [5]; and ETSI TS 136 331 V12.2.0 (2014 Jun.)/3GPP TS 36.331version 12.2.0 Release 12 [6].

In accordance with the terminology and implementation used for carrieraggregation in the context of an LTE-based system, a cell is denoted the‘primary cell’, or Pcell, for a terminal device if it is the cell thatis initially configured during connection setup for the terminal device.Thus the primary cell handles RRC (radio resource control) connectionestablishment/re-establishment for the terminal device. The primary cellis associated with a downlink component carrier and an uplink componentcarrier (CoC). These may sometimes be referred to herein as primarycomponent carriers. A cell that is configured for use by the terminaldevice after initial connection establishment on the Pcell is termed a‘secondary cell’, or Scell. Thus the secondary cells are configuredafter connection establishment on a primary cell to provide additionalradio resources. The carriers associated with Scells may sometimes bereferred to herein as secondary component carriers. Since in LTE up tofive component carriers can be aggregated, up to four Scells(correspondingly associated with up to four secondary componentcarriers) can be configured for aggregation with the primary cell(associated with the primary component carrier). An Scell might not haveboth a downlink and uplink component carrier and the association betweenuplink component carriers and downlink component carriers is signaled inSIB2 on each downlink component carrier. The primary cell supports PDCCHand PDSCH on downlink and PUSCH and PUCCH on uplink whereas thesecondary cell(s) support PDCCH and PDSCH on downlink and PUSCH onuplink, but not PUCCH. Measurement and mobility procedures are handledon the Pcell and the Pcell cannot be de-activated. The Scell(s) may bedynamically activated and deactivated, for example according to trafficneeds, though MAC layer signaling to the terminal device. An Scell for aterminal device may also be deactivated automatically (time out) if theterminal device does not receive any transmission resource allocationson the Scell for a threshold amount of time.

Some aspects of physical layer control signaling for an LTE-basedimplementation of carrier aggregation based on the current standards arenow described.

Each downlink component carrier has the normal LTE control channels:(E)PDCCH, PCFICH and PHICH. However, carrier aggregation introduces thepossibility of so-called cross-carrier scheduling (XCS) on PDCCH. Tosupport cross-carrier scheduling, a downlink control information (DCI)message on PDCCH includes a carrier indicator field (CIF) comprisingthree bits to indicate which of the component carriers the PDCCH messageapplies to. If there is no CIF, the PDCCH is treated as applying to thecarrier on which it is received. A motivation for providingcross-carrier scheduling primarily applies for heterogeneous network(het-net) scenarios where overlaid macro- and small-cells may operatecarrier aggregation in the same band. The effects of interferencebetween the respective macro- and small-cells' PDCCH signaling can bemitigated by having the macro-cell transmit its PDCCH signaling on onecomponent carrier at relatively high transmit power (to provide coverageacross the macro-cell), while the small-cells use an alternativecomponent carrier for their PDCCH scheduling.

The control region supporting PDCCH may differ in size (i.e. number ofOFDM symbols) between component carriers, so they can carry differentPCFICH values. However, the potential for interference in the controlregion in a het-net implementation may mean that PCFICH cannot bedecoded on a particular component carrier. Therefore, current. LTEstandards allow for each component to carrier a semi-static indicationof which OFDM symbol PDSCH can be assumed to begin in each subframe. Iffewer OFDM symbols are actually used for the control region, thefree/spare OFDM symbol(s) may be used for PDSCH transmissions toterminal devices which are not being cross-carrier scheduled as theywill decode the actual PCFICH. If more OFDM symbols actually used forthe control region, there will be some degree of performance degradationfor the cross-carrier scheduled terminal devices.

PHICH signaling is sent on the downlink component carrier that sent thePDCCH signaling containing the PUSCH allocation to which the PHICHsignaling relates. Accordingly, one downlink component carrier may carryPHICH for more than one component carrier.

In the uplink, the basic operation of PUCCH is not altered by theintroduction of carrier aggregation. However, a new PUCCH format (format3) is introduced to support the sending of acknowledgement signaling(ACK/NACK signaling) for multiple downlink component carriers, and withsome alterations to format 1b to increase the number of ACK/NACK bits itcan carry.

To assist good uplink channel sounding, SRS (sounding reference symbols)can be configured on any serving cell in accordance with specifiedoperating rules regarding how signaling on PUSCH, PUCCH and SRS acrossmultiple cells may be arranged to help ensure an appropriate priorityfor the various transmissions is achieved.

In current LTE-based carrier aggregation scenarios, primary andsecondary synchronisation signaling (PSS and SSS) are transmitted on allcomponent carriers using the same physical-layer cell identity (PCI) andcomponent carriers are all synchronised with one another. This can helpwith cell search and discovery procedures. Issues relating to securityand system information (SI) are handled by the Poe. In particular, whenactivating an Scell, the Pcell delivers the relevant SI for the Scell tothe terminal device using dedicated RRC signaling. If the systeminformation relating to a Scell changes, the Scell is released andre-added by Pcell RRC signaling (in one RRC message). Pcell changes,e.g. due to long-term fluctuations in channel quality across the Poebandwidth, are handled using a modified handover procedure. The sourcePcell passes all the relevant carrier aggregation (CA) information tothe target Pcell so the terminal device can begin to use all theassigned component carriers when handover is complete.

Random access procedures are primarily handled on the uplink componentcarrier of Pcell for a terminal device, although some aspects ofcontention resolution signaling may be cross-carrier scheduled toanother serving cell (i.e. an Scell).

As noted above, carrier aggregation is one approach for making use ofunlicensed radio spectrum resources in wireless communication networkswhich are primarily designed to use licensed radio spectrum. In broadsummary, a carrier aggregation based approach may be used to configureand operate a first component carrier (e.g. a primary component carrierassociated with a Pcell in LTE terminology) within a region of the radiospectrum that has been licensed for use by a wireless telecommunicationsnetwork, and to also configure and operate one or more further componentcarriers (e.g. a secondary component carrier associated with an Scell inLTE terminology) in an unlicensed region of the radio spectrum. Thesecondary component carrier(s) operating in the unlicensed region of theradio spectrum may do so in an opportunistic manner by making use of theunlicensed radio resources when they are available. There may also beprovisions made for restricting the extent to which a given operator canmake use of the unlicensed radio resources, for example by defining whatmight be referred to as politeness protocols.

Although known carrier aggregation schemes can form a basis for usingunlicensed radio spectrum resources (or other forms of shared radioresources) in conjunction with licensed radio spectrum resources, somemodifications to known carrier aggregation techniques may be appropriateto help optimise performance. This is because radio interference in theunlicensed radio spectrum can be expected to be subject to a wider rangeof unknown and unpredictable variations in time and frequency than mightbe seen within a region of the radio spectrum which has been licensedfor use by a particular wireless applications system. For a givenwireless telecommunications system operating in, accordance with a giventechnology, such as LTE-A, interference in the unlicensed radio spectrummay arise from other systems operating with the same technology, orsystems operating according to different technologies, such as Wi-Fi,Bluetooth or global satellite navigation systems, GNSS.

Communications with a terminal device which take advantage of unlicensedspectrum operation can therefore be subject to unpredictableinterference from other devices operating in the radio environment ofthe terminal device. In this regard, and as noted above, the otherdevices may be operating in accordance with the same radio accesstechnology (e.g. they may be other terminal devices associated withanother LTE network which is making use of the same unlicensed spectrum)and or they may be devices operating in the unlicensed spectrum inaccordance with a different radio access technology, such as Wi-Fi,Bluetooth of GNSS (it be appreciated that in a GNSS context the terminaldevice will typically be communicating through reception withouttransmission).

In addition to inter-device interference issues, it is possible forinterference issues to arise from a source within a terminal deviceitself. For example, it has become commonplace for terminal devices tobe provided with wireless LAN (e.g. Wi-Fi), Bluetooth and satellitepositioning functionality in addition to cellular-communication (e.g.LTE) functionality. The ability of a terminal device to reliably accessradio resources for cellular communications can thus be impacted if theterminal device is also accessing radio resources for wirelesscommunications associated with other radio access technologies, and viceversa. This kind of intra-device interference is sometimes referred toas in-device coexistence (IDC) interference/the IDC problem. In somerespects IDC interference issues can be more severe than inter-deviceinterference issues because of the immediate proximity of thetransceiver circuitry associated with the different wireless radioaccess technologies in the terminal device.

The IDC problem has previously been considered in the context ofconventional cellular communications operating on licensed bandsadjacent to frequency bands comprising radio resources used by otherpotentially interfering radio access technologies. For example, in somegeographic areas the radio band 2400-2483.5 MHz (the industrial, medicaland scientific (ISM) band) is used for Wi-Fi and Bluetoothcommunications, while neighbouring bands, such as the 2300-2400 MHz band(Band 40 for TDD mode) and the 2500-2570 MHz band (Band 7 for FDD modeUL), are useful cellular communications. As a consequence, cellularcommunications in these bands can be prone to interference from Wi-Fiand Bluetooth communications in the adjacent ISM band. Global NavigationSatellite Systems (GNSS) can operate on various frequencies and cellularcommunications on frequencies around GNSS frequencies can likewiseinterfere with a terminal device's ability to operate a GNSS receiver.

More details on the issues associated with in-device coexistenceinterference and proposed solutions in the context of inter-bandinterference in an LTE wireless telecommunications system can be foundin the technical documents associated with the relevant operatingstandards. For example, in the context of LTE-based networks, ETSI TR136 816 V11.2.0 (2011 Dec.)/3GPP TR 36.816 version 11.2.0 Release 11provides a study on signaling and procedures for interference avoidancefor in-device coexistence; ETSI TS 136 300 V12.2.0 (2014 Jun.)/3GPP TS36.300 version 12.2.0 Release 12 [8] sets out the adopted solutions tothe IDC problem—see for example Section 23.4. In summary, the approachis for a terminal device to identify when DC problems arise in respectof frequencies which the terminal device is configured to measure(measurement objects) and which the terminal device cannot solve byitself and to send a corresponding IDC indication report to the networkvia dedicated RRC signaling to report the issue. In accordance with thecurrent LTE standards, this report is sent as an InDeviceCoexIndicationmessage in accordance with the approach set out in ETSI TS 136 331V12.2.0 (2014 Jun.)/3GPP TS 36.331 version 12.2.0 Release 12 [6]—seeSection 5.6.9 for an overview of the signaling and Section 6.2.2 for anoverview of the message format. On receiving an InDeviceCoexIndicationreport indicating a potential problem for a terminal device, the networkmay then take appropriate action to seek to mitigate the issue. This mayinclude, for example, handing over the terminal device'stelecommunications to another carrier frequency, or configuring theterminal device for a time division duplex solution on the currentcarrier frequency.

Existing approaches for handling IOC issues do not consider thesituation in which cellular communications may be undertaken on samefrequencies (as opposed to adjacent frequencies) as other radio accesstechnologies, for example in an LTE-U mode of operation. The inventorhas recognised how modifications to existing approaches for handling IDCissues may be needed to optimise cellular communications usingunlicensed radio spectrum in a device which also uses the unlicensedradio spectrum for wireless communications associated with otherwireless access technologies, such as Bluetooth, WLAN (e.g. Wi-Fi) andGNSS.

FIG. 4 schematically shows a telecommunications system 400 according toan embodiment of the disclosure. The telecommunications system 400 inthis example is based broadly on a LTE-type architecture. As such manyaspects of the operation of the telecommunications system 400 arestandard and well understood and not described here in detail in theinterest of brevity. Operational aspects of the telecommunicationssystem 400 which are not specifically described herein may beimplemented in accordance with any known techniques, for exampleaccording to the established LTE-standards and known variations thereof.

The telecommunications system 400 comprises a core network part (evolvedpacket core) 402 coupled to a radio network part. The radio network partcomprises a base station (evolved-nodeB) 404, a first terminal device406 and a second terminal device 408. It will of course be appreciatedthat in practice the radio network part may comprise a plurality of basestations serving a larger number of terminal devices across variouscommunication cells. However, only a single base station and twoterminal devices are shown in FIG. 4 in the interests of simplicity.

Although not part of the cellular telecommunications system 400 itself,also shown, in FIG. 4 are some other devices which, are operable towirelessly communicate with one another and which are operating withinthe radio environment of the telecommunications system 400. Inparticular, there is a pair of wireless access devices 416 communicatingwith one another via radio link 418 operating in accordance with a Wi-Fistandard and a pair of Bluetooth devices 420 communicating with, oneanother via radio link 422 operating in accordance with a Bluetooth,standard. These other devices represent a potential source of radiointerference for the telecommunications system 400. It will beappreciated that in practice there will typically be many more suchdevices operating in the radio environment of the wirelesstelecommunications system 400, and only two pairs of devices 416, 420are shown in FIG. 4 for simplicity.

As with a conventional mobile radio network, the terminal devices 406,408 are arranged to wirelessly communicate data to and from the basestation (transceiver station) 404. The base station is in turncommunicatively connected to a serving gateway, S-GW, (not shown) in thecore network part which is arranged to perform routing and management ofmobile communications services to the terminal devices in thetelecommunications system 400 via the base station 404. In order tomaintain mobility management and connectivity, the core network part 402also includes a mobility management entity (not shown) which manages theenhanced packet service, EPS, connections with the terminal devices 406,408 operating in the communications system based on subscriberinformation stored in a home subscriber server, HSS. Other networkcomponents in the core network (also not shown for simplicity) include apolicy charging and resource function, PCRF, and a packet data networkgateway, PDN-GW, which provides a connection from the core network part402 to an external packet data network, for example the Internet. Asnoted above, the operation of the various elements of the communicationssystem 400 shown in FIG. 4 may be broadly conventional apart from wheremodified to provide functionality in accordance with embodiments of thedisclosure as discussed herein.

The terminal devices 406, 408 each comprise a transceiver unit 406 a,408 a for transmission and reception of wireless signals and acontroller unit 406 b, 408 b configured to control the operation of therespective devices 406, 408 in accordance with embodiments of thedisclosure. The respective controller units 406 b, 408 b may eachcomprise a processor unit which is suitably configured programmed toprovide the desired functionality described herein using conventionalprogramming configuration techniques for equipment in wirelesstelecommunications systems. For each of the terminal devices 406, 408,their respective transceiver units 406 a, 408 a and controller units 406b, 408 b are schematically shown in FIG. 4 as separate elements for easeof representation. However, it will be appreciated that for eachterminal device the functionality of these units can be provided invarious different ways, for example using a single suitably programmedgeneral purpose computer, or suitably configured application-specificintegrated circuit(s)/circuitry, or using a plurality of discretecircuitry/processing elements for providing different elements of thedesired functionality. It will be appreciated the terminal devices 406,408 will in general comprise various other elements associated withtheir operating functionality in accordance with established wirelesstelecommunications techniques (e.g. a power source, possibly a userinterface, and so forth).

As has become commonplace in the field of wireless telecommunications,the terminal devices 406, 408 support radio communications in accordancewith a plurality of different radio access technologies. For example, inaddition to communicating wirelessly with the base station in accordancewith a cellular communications radio access technology, such as LTE, theterminal devices 406, 408 may also communicate with other devices inaccordance with other radio access technologies, such as wireless localarea network radio access technologies (e.g. Wi-Fi), short distanceradio access technologies (e.g. Bluetooth), and global navigationsatellite system radio access technologies (e.g. GPS). Thus, theterminal devices 406, 408 represented in FIG. 4 support Wi-Fi, Bluetoothand GPS functionality in addition to cellular/mobile telecommunicationsfunctionality. Consequently, the respective terminal devices 406, 408may also communicate with other devices operating in the network usingnon-cellular radio access technologies. Some examples of thisnon-cellular functionality is schematically represented in FIG. 4 withthe first terminal device 406 communicating with one of the wirelessaccess devices 416 over a wireless link 424 operating in accordance witha Wi-Fi radio access technology standard, the second terminal devicecommunicating with one of the Bluetooth devices 420 over a wireless link426 operating in accordance with a Bluetooth radio access technologystandard, and with the first terminal device 406 receiving globalpositioning satellite signaling from a plurality of global positioningsatellites 428 over corresponding wireless links 430 operating inaccordance with a global positioning satellite system radio accesstechnology.

Thus the transceiver units 406 a, 408 a of the respective terminaldevices may comprise functional modules operable according to differentwireless communications operating standards. For example, the terminaldevices' transceiver units may each comprise an LTE transceiver modulefor supporting wireless communications in accordance with an LTE-basedoperating standard, a Wi-Fi transceiver module for supporting wirelesscommunications in accordance with a MAN operating standard, a Bluetoothtransceiver module for supporting wireless communications in accordancewith a Bluetooth operating standard, and a GPS transceiver module forsupporting wireless communications in accordance with a GNSS operatingstandard. It will be appreciated the GPS transceiver module willgenerally be restricted to receive functionality, but is nonethelessreferred to here as a transceiver module for convenience of terminology.The underlying functionality of the different transceiver modules may beprovided in accordance with conventional techniques. For example, aterminal device may have separate hardware elements to provide thefunctionality of each transceiver module, or alternatively, a terminaldevice might comprise at least some hardware elements which areconfigurable to provide some or all functionality of multipletransceiver modules. Thus the transceiver units 406 a, 408 a of theterminal devices 406, 408 represented in FIG. 4 are assumed here toprovide the functionality of an LTE transceiver module, a Wi-Fitransceiver module, a Bluetooth transceiver module and a GPS transceivermodule in accordance with conventional wireless communicationstechniques.

The base station 404 comprises a transceiver unit 404 a for transmissionand reception of wireless signals and a controller unit 404 b configuredto control the base station 404. The controller unit 404 b may comprisea processor unit which is suitably configured/programmed to provide thedesired functionality described herein using conventionalprogramming/configuration techniques for equipment in wirelesstelecommunications systems. The transceiver unit 404 a and thecontroller unit 404 b are schematically shown in FIG. 4 as separateelements for ease of representation. However, it will be appreciatedthat the functionality of these units can be provided in variousdifferent ways, for example using a single suitably programmed generalpurpose computer, or suitably configured application-specific integratedcircuit(s)/circuitry or using a plurality of discretecircuitry/processing elements for providing different elements of thedesired functionality. It will be appreciated the base station 404 willin general comprise various other elements associated with its operatingfunctionality. For example, the base station 404 will in generalcomprise a scheduling entity responsible for scheduling communications.The functionality of the scheduling entity may, for example, be subsumedby the controller unit 404 b.

Thus, the base station 404 is configured to communicate data with thefirst and second terminal devices 406, 408 over respective first andsecond radio communication links 410, 412. The wirelesstelecommunications system 400 supports a carrier aggregation mode ofoperation in which the first and second radio communication links 410,412 each comprise a wireless access interface provided by multiplecomponent carriers. For example, each radio communication link maycomprise a primary component carrier and one or more secondary componentcarriers. Furthermore, the elements comprising the wirelesstelecommunications system 400 in accordance with this embodiment of thedisclosure are assumed to support carrier aggregation in an unlicensedspectrum mode. In this unlicensed spectrum mode the base stationcommunicates with terminal devices using a primary component carrieroperating on radio resources within a first frequency band that has beenlicensed for use by the wireless telecommunications system and one ormore secondary component carriers operating on radio resources within asecond frequency band that has not been licensed for exclusive use bythe wireless telecommunications system. The first frequency band maysometimes be referred to herein as a licensed frequency band and thesecond frequency band may sometimes be referred to herein as anunlicensed (U) frequency band. In the context of an LTE-based wirelesstelecommunications system, such as that represented in FIG. 4, operationin the unlicensed frequency band may be referred to as an LTE-U mode ofoperation. The first (licensed) frequency band may be referred to as anLTE band (or more particularly an LTE-A band) and the second(unlicensed) frequency band may be referred to as an LTE-U band.Resources on the LTE-U band may be referred to as U-resources. Aterminal device able to make use of U-resources may be referred to as aU-terminal device (or U-UE). More generally, the qualifier “U” may beused herein to conveniently identify operations in respect of theunlicensed frequency hand.

It will be appreciated that the use of carrier aggregation techniquesand the use of unlicensed spectrum resources (i.e. resources that may beused by other devices without centralised coordination) in accordancewith embodiments of the disclosure may be based generally on previouslyproposed principles for such modes of operation, for example asdiscussed above, but with modifications as described herein to provideadditional functionality in accordance with embodiments of the presentdisclosure. Accordingly, aspects of the carrier aggregation andunlicensed spectrum operation which are not described in detail hereinmay be implemented in accordance with known techniques.

Modes of operation for the wireless telecommunications network 400represented in FIG. 4 in accordance with certain embodiments of thedisclosure will now be described. The general scenario for theseembodiments is assumed to be one in which a carrier aggregation capableterminal device is operating in an LTE-A cell as normal, and the basestation determines that it should configure the LTE-U′ capable terminaldevice with an additional aggregated carrier using LTE-U resources. Thespecific reason why the base station determines that it should configurea particular terminal device for LTE-U based carrier aggregation is notsignificant. Thus the LTE-A carrier provides a Pcell for the terminaldevice and the LTE-U resources provide one or more Scell(s) for theterminal device. It will be appreciated the LTE-A resources may also beused to provide component carriers associated with one or more furtherScells(s) in accordance with conventional carrier aggregationtechniques. For the examples described with reference to FIG. 4, theLTE-A transmissions in the licensed frequency band and the LTE-Utransmissions in the unlicensed frequency band, and thus the Pcell andScell(s), are both made from the same base station 404, but this may notbe the case in other example embodiments. The LTE-U carrier could ingeneral be utilised with a TDD (time division duplex) or FDD (frequencydivision duplex) frame structure. However, a consequence of some aspectsof existing regulatory restrictions on unlicensed spectrum usage in someregions means that TDD or downlink-only FDD operation may, at leastcurrently, be more likely.

FIG. 5 is a signaling ladder diagram schematically representing modes ofoperation for one of the terminal devices (UEs) 405, 459 and the basestation (eNB) 404 schematically represented in FIG. 4 in accordance withcertain embodiments of the present disclosure. The operation is forsupporting communications between the base station and the terminaldevice in accordance with a first radio access technology (e.g. anLTE-based radio access technology) using a primary component carrier(associated with a primary cell) operating on radio resources within afirst frequency band and a secondary component carrier (associated witha secondary cell) operating on radio resources within a second frequencyband in accordance with certain embodiments of the present disclosure.As discussed above, the first frequency band is taken to correspond withresources that have been licensed for dedicated use by the operator ofthe wireless telecommunications system 400 for cellular communications,whereas the second frequency band is taken to correspond with resourcesthat are shared by other wireless communication technologies which theterminal device may support.

In broad summary, some embodiments of the disclosure introduce theconcept of a terminal device determining if there is an overlap(conflict) between radio resources configured by the base station forcommunicating with the terminal device and radio resources which theterminal device wishes to use for communicating in accordance withanother radio access technology, and reporting to the base station ifthere is an overlap. The base station may then respond by selecting anew configuration of radio resources for communicating with the terminaldevice, and transmitting this to the terminal device, as discussedfurther below.

Processing in accordance with certain embodiments of the disclosure asschematically represented in FIG. 5 is shown starting from a stage atwhich the terminal device is configured for operation on the primarycell associated with the primary carrier, but is not yet configured foroperation on the secondary cell associated with the secondary carrier.This may be, for example, because the terminal device has only justconnected to the primary cell or because a previous secondary cellconfiguration is no longer valid. It is also assumed in this example theUE is not wirelessly communicating with any other devices using itsBluetooth or GPS functionality at the start of the processingrepresented in FIG. 5, but this is not of particular significance.

In step S1 the base station establishes a measure of radio usage in thesecond frequency band. In some example implementations the base stationmay itself measure radio usage at different frequencies across thesecond frequency band, but in this example it is assumed the terminaldevice makes these measurements and reports them to the base station.That is to say, in this example implementation the base stationestablishes radio usage across the second band (unlicensed band) fromreports received from the terminal device (and/or other terminal devicesoperating in the wireless telecommunications system). This informationcan help the base station determine whether, and if so how, a secondarycomponent carrier might be configured for to support cellularcommunications with the terminal device in the unlicensed frequencyband.

Thus, the terminal device makes measurement of radio usage in the secondfrequency band in its environment. In particular, the terminal devicemeasures the degree of radio usage at different frequencies across thesecond frequency band. For example, the terminal device may use its WLANtransceiver module to scan for activity associated with other wirelesscommunication devices, for example, Wi-Fi access points. From this theterminal device may establish, for example, an indication of frequencyresources used by other wireless communications devices and or anindication of a received signal strength for wireless communicationsassociated with other wireless communications devices and/or anindication of an identifier for the other wireless communications device(e.g. SSID). The terminal device may also scan for radio usage in thesecond frequency band by other devices operating according to otheroperating standards, for example Bluetooth and or other LTE networks. Insome embodiments the terminal device might not separately measure radiousage by different technologies, but may simply measure an aggregatelevel of radio signals (which may include radio noise) in itsenvironment at different frequencies across the second frequency band.The terminal device then transmits an indication of the measurements ofradio usage at different frequencies across the second frequency band tothe base station. This may be done on uplink radio resources on thealready-configured primary cell to which the terminal device isconnected in accordance with conventional signaling techniques, forexample in accordance with the established principles of measurementreport RRC signaling. Based on the measurement information regardingradio usage in the second frequency band received from the terminaldevice, the base station establishes radio usage across the secondaryband in step S1 represented in FIG. 5.

In Step S2, the base station determines a configuration setting for thesecondary component carrier based on the radio usage in the secondfrequency band established in step S1. For example, the configurationsetting may define transmission resources (e.g. in terms of time and/orfrequency resources) selected from within the second frequency band touse for the secondary component carrier. The base station may determineappropriate transmission resources for the secondary cell configurationfrom the received measurements of radio usage in accordance with anyestablished techniques for selecting appropriate transmission resourcesto use in a competitive (opportunistic) radio environment based onmeasurements of existing usage. For example, the base station may seekto avoid configuring radio resources in regions of the second frequencyband for which the terminal device measurement reports indicate arelatively high degree of radio usage, and may instead preferentiallyselect a configuration for the secondary carrier that makes use of radioresources in spectral regions having a relatively low degree of radiousage.

In general, the process of determining an appropriate configurationsetting (e.g. determining an appropriate carrier frequency) for asecondary carrier for supporting cellular communications with a terminaldevice in a portion of the radio spectrum which is also used by otherradio access technologies (i.e. radio access technologies which aredifferent from cellular radio access technologies) may be performed inaccordance with any previously proposed techniques.

In step S3 the base station transmits an indication of the chosenconfiguration setting for the secondary carrier to the terminal device.This may be done on downlink radio resources on the already-configuredprimary cell in accordance with conventional signaling techniques, forexample in accordance with the established principles of radio bearer(re)configuration message RRC signaling. In accordance with certainembodiments of the disclosure, the indication of the chosenconfiguration setting for the secondary carrier may be associated withan indication for enabling in-device coexistence (IDC) reporting inaccordance with embodiments of the disclosure. In some implementationsthis may comprise a dedicated flag which may be set by the base stationto actively indicate whether or not DC reporting should be undertaken bythe terminal device in respect of the relevant configuration. The flagmay be conveyed, for example, in a new information element defined forradio bearer reconfiguration signaling of the type used in step S3. Inother implementations, the triggering of IDC reporting in respect of theconfigured radio resources associated with the signaling step S3 may beimplicit, for example, simply receiving a conventional radio bearerreconfiguration message in respect of radio resources associated with apredefined portion of the radio spectrum (corresponding to theunlicensed portion of the radio spectrum) may be interpreted by theterminal device as an indication for enabling IDC reporting inaccordance with certain embodiments of the disclosure as describedfurther below. In this respect, the terminal device may in effect beconfigured to establish a measurement object in respect of the radioresources configured for supporting the secondary carrier in response toreceiving the indication for enabling IDC reporting in step S3. That isto say, the terminal device may determine that the relevant radioresources should be monitored without necessarily receiving a specificmeasurement configuration setting identifying the resources as ameasurement object.

In response to receiving the signaling configuring the secondary carrierin step S3, the terminal device configures its transceiver unit (and inparticular the LTE transceiver module component of its transceiver unit)in accordance with the configuration setting information received fromthe base station, for example by appropriate tuning of the transceivercircuitry. This may be formed in accordance with conventional techniquesfor radio bearer configuration setting. The base station may then startcommunicating with the terminal device using the primary carrier and thesecondary carrier configured in accordance with the latest configurationsetting for the secondary component carrier. This may be done based onestablished carrier aggregation techniques and using previously-proposedtechniques for making use of unlicensed frequency spectrum. Thispotentially ongoing cellular communication aspect of the operation isnot represented in FIG. 5.

In step S4 the terminal device begins monitoring for in-devicecoexistence conflict with respect to the radio resources configured forthe second carrier and the resources which the terminal device wishes touse for communicating in accordance with another radio accesstechnology, for example Wi-Fi. That is to say, having received from thebase station an indication of a configuration of radio resources withinthe second frequency band for use by the terminal device forcommunications with the base station in accordance with a first radioaccess technology (i.e. LTE cellular communications in this example),the terminal device establishes a configuration of radio resourceswithin the second frequency band for use by the terminal device forcommunications in accordance with a second radio access technology (e.g.Wi-Fi). The configuration of resources to be used for Wi-Ficommunications may be established in accordance with conventionaltechniques. The monitoring of step S4 corresponds with the terminaldevice determining, on an ongoing basis, whether there is an overlap inthe radio resources configured for use by the terminal device forcommunications in accordance with the first radio access technology(i.e. the radio resources configured for supporting the secondarycarrier) and the radio resources configured for use by the terminaldevice for communications in accordance with the second radio accesstechnology (i.e. the radio resources the terminal device needs for Wi-Ficommunications). The monitoring of Step S4 may be performed inaccordance with a monitoring schedule corresponding to that used forconventional inter-frequency IOC monitoring.

In the processing represented in FIG. 5 it is assumed that in step S5the terminal device determines there is an overlap (conflict) in respectof the radio resources configured for use by the secondary carrier andthe radio resources which the terminal devices own Wi-Fi module requiresfor Wi-Fi communications.

That is to say, the terminal device determines that the radio resourcescurrently configured for supporting the secondary carrier are alsoneeded for supporting Wi-Fi communications (it will be appreciated thisexample is described in the context of competing Wi-Fi communications,but the same principles apply for Bluetooth and GPS communications, ormore generally, for any communications in accordance with any radioaccess technology supported by the terminal device which is differentfrom the radio access technology used for communications with the basestation on the secondary carrier).

In step S6 the terminal device sends an overlap/conflict report to thebase station to indicate the existence of the overlap. This may be senton uplink radio resources associated the primary carrier. In accordancewith certain embodiments this conflict report may generally conform toan existing format for reporting inter-frequency IDC interferenceissues, for example in accordance with the principles set out in [6],[7] and [8]. In an LTE context, an InDeviceCoexIndication message formatis defined for reporting inter-frequency IDC interference issues. Inthis regard, a conventional InDeviceCoexIndication message can onlyprovide feedback in respect of frequencies which have been configured asmeasurement objects for the terminal device. Furthermore, there is alimited amount of information which the terminal device can convey tothe base station with a conventional InDeviceCoexIndication message. Forexample, the terminal device can indicate the frequency subject tointer-frequency IDC and the direction of interference (i.e. whether theLTE communications are causing interference or are being interferedwith, or both). Therefore, in accordance with certain embodiments of thedisclosure it is proposed to introduce a new information element to theexisting InDeviceCoexIndication message format to indicate whether radioresources configured for the secondary carrier are associated with anoverlap with radio resources needed for communicating in accordance witha non-cellular radio access technology. That is to say, the terminaldevice may be configured to configure an InDeviceCoexIndication messagewith an entry associated with the configured secondary carrier with acorresponding information element which is set to one value to indicateno overlap and another value to indicate overlap. In this regard, thesignaling transmitted to the network to indicate there is an overlap maycomprise radio resource control, RRC, signaling. However, it will beappreciated there are many different ways in which an indication of theoverlap/conflict may be reported to the network in accordance with otherembodiments of the disclosure, and some examples of these are describedfurther below.

In step S7, having received the indication of the overlap from theterminal device in step S6, the base station determines a replacementconfiguration setting for the secondary component carrier. Step S6 maybe performed largely in the same way as step S2 described above, but inaddition to taking account of measurements of radio usage across thesecond (unlicensed/shared) frequency band, the base station also takesaccount of the overlap report received from the terminal device, and inparticular avoids configuring any of the radio resources in respect ofwhich the overlap is indicated in the replacement configuration settingestablished in step S7.

In the processing represented in FIG. 5, it is assumed the base stationis able to determine an appropriate replacement configuration settingfor the secondary carrier. However, in some cases it may be that theoverlap and/or current radio usage across the unlicensed frequency bandprevents the base station from determining an appropriate replacementconfiguration. For example, if there is only a limited number ofpotential configurations available for the secondary carrier and theseare all inappropriate because of the overlap with radio resources neededby the terminal device to support its non-cellular communications, thebase station may determine that it is unable to configure the terminaldevices for secondary carrier operation at the present time. In thiscase, the base station may simply indicate to the terminal device thatthe previously-received configuration setting in step S3 is to beconsidered no longer valid without seeking to provide a replacementconfiguration. This may be done by sending conventional releasesignaling.

However, in the processing of FIG. 5 it is assumed the base station isable to determine an appropriate replacement configuration in step S7,and in step S8 the base station transmits an indication of the chosenreplacement configuration setting for the secondary carrier to theterminal device. This step that may be performed in the same manner asdescribed above in respect of step S3 for the previously-determinedconfiguration setting.

In step S9 the terminal device determines if the replacementconfiguration for the secondary carrier includes radio resources inrespect of which the terminal device indicated there was an overlap instep S6.

If it does not, the terminal device may proceed to operate normally asdescribed above. That is to say, the terminal device may undertakecommunications as necessary, while also continuing to monitor for theoccurrence of an overlap in the radio resources currently configured forsupporting the secondary carrier for cellular communications with thebase station, and the radio resources that are needed for communicatingin accordance with a different radio access technology. It will beappreciated the radio resources needed for communicating in accordancewith the other radio access technologies, such as Wi-Fi. Bluetooth andGPS, may change with time according to the terminal device's currentactivities. For example, at some point in time the terminal device maynot be undertaking any Wi-Fi communications, whereas at other points intime it may be undertaking Wi-Fi communications. Furthermore, if theterminal device may switch from being connected to one Wi-Fi accesspoint to being connected to another Wi-Fi access point, and accordinglythere may be a change in the configuration of radio resources needed forsupporting Wi-Fi communications which may give rise to an overlap withan existing configuration of radio resources for cellularcommunications.

However, if in step S9 it is determined that the replacementconfiguration received from the base station in step S8 includes radioresources that the terminal device has previously indicated are subjectsto overlap, the terminal device may be configured to treat theconfiguration received in step S8 as being an invalid configuration.That is to say, the terminal device may react in the same way as if ithad been instructed to adopt a configuration which it was not capable ofadopting in accordance with its capabilities. For example, the terminaldevice may revert to a radio resource control, RRC, idle mode in respectof the secondary component carrier in such an event. In anotherimplementation, the terminal device may simply send another conflictreport in respect of the replacement configuration corresponding to thesignaling sent in step S6 in respect of the previous configuration.

Thus, the processing represented in FIG. 5 provides a scheme forallowing a terminal device to indicated to a base station that acurrent-configuration of radio resources for supporting a secondarycomponent carrier in a region of the spectrum that may be used by theterminal device for communicating in accordance with another radioaccess technology cannot be used for supporting the secondary carrier.

It will be appreciated there are many variations of the processingrepresented in FIG. 5 that can be adopted in accordance with differentimplementations of embodiments of the disclosure.

For example, rather than introduce a new information element into anexisting InDeviceCoexIndication message format, a current field of anexisting InDeviceCoexIndication message format may be repurposed toprovide an indication of overlap in respect of radio resources withwhich corresponding entry in the InDeviceCoexIndication message relates.For example, in an LTE context, there is currently an unused (i.e.spare) value available in the information element relating to theinterference direction field of the existing InDeviceCoexIndicationmessage format. In accordance with some embodiments of the disclosure,this value may be selectively set by the terminal device to indicate theradio resources to which the corresponding entry in theInDeviceCoexIndication message relates are subject to overlap withresources that the terminal device is seeking to use for communicatingin accordance with another wireless access technology.

In other example implementations, the report signaling transmitted instep S6 of the processing represented in FIG. 5 may not be sent as an anaspect of an InDeviceCoexIndication message using RRC signaling. Forexample, a dedicated signaling format may be established for conveyingthis information. Alternatively, an existing reporting process may bere-purposed to provide an indication of overlap. For example, theterminal device may be configured to provide CQI reporting in respect ofthe secondary carrier currently configured by the base station and a CQIvalue may be predefined to correspond with an indication of overlap inrespect of the relevant radio resources. Thus, a terminal device mayprovide CQI reports in respect of the configured secondary carrier inthe usual way until it is determined that there is a conflict/overlapwith the terminal device's needs for using the relevant radio resourcesfor communicating in accordance with another radio access technology,and in this case may provide a CQI report conveying a CQI value which ispredefined as being for use when indicating the radio channel isunusable because of the overlap. The relevant CQI value to use toindicate overlap may be specified in accordance with a standard of thewireless communications system, or established in prior communicationsbetween the base station and terminal device. This approach may in somecases provide faster feedback as there is no need for the RRC signalingoverhead associated with an InDeviceCoexIndication message.

It will be appreciated the report indicating the existence of a radioresource conflict/overlap may further convey additional information tothe base station which may be useful in helping the base stationestablish an appropriate updated configuration setting. For example, thereport may also indicate the nature of the radio access technology forwhich the radio resources are overlapping with the radio resourcesconfigured for supporting the secondary carrier and the unlicensed band.For example, the report may indicate that the overlap is in respect ofwireless local area network communications, or Bluetooth communications,or GPS receiver communications. Because it can be expected the differenttypes of communications have different operating profiles, for examplein terms of bandwidth and the likely duration of an identified overlap,this kind of additional information may in some circumstances assist thebase station in selecting an appropriate re-configuration for thesecondary carrier radio resources.

The processing represented in FIG. 5 is based on an approach in whichthe base station provides the terminal device with a single currentconfiguration setting for the secondary carrier. However, there havebeen proposed approaches in which a plurality of potential configurationsettings are established for a single secondary carrier. This can allowthe base station to more rapidly switch between configuration settings,for example in response to changing radio conditions on the unlicensedradio band. An example of this approach is set out in co-pendingapplication EP14171284.4 [9] filed on 5 Jun. 2014, the entire contentsof which are incorporated herein by reference. In broad summary, in anexample of this kind of approach a terminal device and networkinfrastructure equipment in a wireless telecommunications systemcommunicate on a primary cell supporting a primary component carrier onradio resources within a first frequency band and a secondary cellsupporting a secondary component carrier on radio resources within asecond frequency band. The infrastructure equipment establishes aplurality of configuration settings for the secondary carrier (e.g. interms of frequency and or time resources) based on measurements of radiousage in the second frequency band. The configuration settings (whichmay in some respects be viewed as semi-static secondary cellpre-configurations) are conveyed to the terminal device. The terminaldevice makes channel quality measurements for the secondary componentcarrier according to the different configuration settings and reportsthese to the infrastructure equipment. Based on these measurements ofchannel quality for the different configurations of the secondarycarrier, the infrastructure equipment selects one of the configurationsettings, and conveys an indication of this to the terminal device inassociation with an allocation of transmission resources on thesecondary component carrier. Data is then transmitted from theinfrastructure equipment to the terminal device using the allocatedresources on the secondary component carrier with the secondarycomponent carrier operating in accordance with the selectedconfiguration.

Thus, in some implementations processing steps corresponding to steps S2and S3 of FIG. 5 may be associated with multiple potential configurationsettings. In this case, the terminal device may be configured todetermine whether any of the potential configuration settings aresubject to overlap with the radio resources which the terminal device isto use for other communications, and if so to provide a conflict reportsimilar to that discussed above, but further indicating which of thepotential configuration settings the overlap applies to.

In accordance with some previously proposed approaches a configurationsetting for a secondary carrier in a unlicensed band may be associatedwith a validity period and may be assumed valid until the validityperiod expires. An example of this approach is set out in co-pendingapplication EP14171285.1 [10] filed on 5 Jun. 2014, the entire contentsof which are incorporated herein by reference. In broad summary, aterminal device and a base station in a wireless telecommunicationssystem communicate with one another using a primary component carrieroperating on radio resources within a first frequency band and asecondary component carrier operating on radio resources within a secondfrequency band. The terminal device makes measurements of radio usage inthe second frequency band, e.g. by other devices which are not part ofthe wireless telecommunications system but which can also use radioresources within the second frequency band. The terminal devicetransmits an indication of the measurements to the base station, and onthe basis of this the base station establishes a configuration settingfor the secondary component carrier, for example in terms of frequencyresources to use for the secondary component carrier. The configurationsetting is associated with a validity period during which the basestation communicates data to the terminal device using the primarycomponent carrier and the secondary component carrier operating inaccordance with its configuration setting. When the validity periodexpires, the terminal device again measures and reports on radio usageso the base station can determine an updated configuration setting forthe secondary component carder that takes account of any changes inradio usage during the validity period. This kind of approach may beadopted in accordance with certain embodiment of the present disclosure,whereby the identification of an overlap represents a trigger forassuming the validity period should be curtailed/cut short. Moregenerally, the terminal device may respond to the identification of anoverlap by releasing the configuration for the carrier in respect ofwhich the overlap is identified.

In the examples described above, the base station establishes a measureof radio usage in the second frequency band in step S1 from reportsreceived from terminal devices operating in the wirelesstelecommunications system. In this regard, and in addition to or insteadof the terminal devices reporting on radio usage in their surroundings(radio environment), the terminal devices may be configured to report tothe base station information regarding their respective use (or intendeduse) of radio resources within the second frequency band forcommunicating in accordance with other radio access technologies. Thebase station may then take this into account when establishing aconfiguration in a step corresponding to step S2, for example byavoiding configuring radio resources for use by a terminal device whichhas indicated a need to use these radio resources for communicating inaccordance with a different radio access technology.

It will be appreciated that while the above-described embodiments arefocused on a single base station supporting both the primary componentcarrier the secondary component carrier, more generally these could betransmitted from separate base stations. In this regard, thenetwork-side processing in accordance with embodiments of the presentdisclosure may be performed by network infrastructure equipment whichcomprises, for example, one base station or more than one base station,and potentially other network infrastructure equipment elementsaccording to the operating principles of the wireless telecommunicationsnetwork in which the approach is implemented.

It will be appreciated the principles described above may be applied inrespect of a wireless telecommunications system supporting carrieraggregation with secondary component carriers operating in a frequencyband over which the wireless telecommunications system does not haveexclusive control irrespective of whether or not the wirelesstelecommunications system requires an administrative license to operatein the secondary frequency band. That is to say, it will be appreciatedthe terminology “unlicensed” is used herein for convenience to refer tooperation in a band over which the wireless telecommunications systemdoes not have exclusive access. In many implementations this willcorrespond with a license exempt frequency band. However, in otherimplementations the operation may be applied in a frequency band whichis not unlicensed in the strict administrative sense, but which isnonetheless available for shared opportunistic use by devices operatingaccording to different wireless access technologies (e.g. LTE-based,Wi-Fi-based and/or Bluetooth-based technologies) and or multiplenetworks operating according to the same technology (e.g. LTE-basedwireless communication systems provided by different network operators).In this regard the terminology such as “unlicensed frequency band” maybe considered to refer generally to a frequency band in which resourcesare shared by different wireless communications systems. Accordingly,while the term “unlicensed” is commonly used to refer to these types offrequency bands, in some deployment scenarios an operator of a wirelesstelecommunications system may nonetheless be required to hold anadministrative license to operate in these frequency bands. Operation ofthe kind described herein is sometimes referred to as being LicenseAssisted Access (LAA) as opposed to being unlicensed. For example, theterm LTE-LAA may be used in place of LTE-U, and so on. This terminologyreflects the nature of the operation in using communications onfrequencies which are licensed for use by an operator to assist accesson other frequencies which are not exclusively licensed for use by theoperator.

Thus there has been described a terminal device and networkinfrastructure equipment that communicate in accordance with a firstradio access technology on a primary cell supporting a primary componentcarrier on radio resources within a first frequency band and a secondarycell supporting a secondary component carrier on radio resources withina second frequency band. The terminal device is also operable to useradio resources within the second frequency band for communicating inaccordance with a second radio access technology, e.g. Wi-Fi. Thenetwork infrastructure equipment establishes a configuration of radioresources (a channel) within the second frequency band for use by theterminal device for communications with the network infrastructureequipment in accordance with the first radio access technology andcommunicates an indication of this to the terminal device (i.e. aconfiguration for the secondary component carrier). The terminal deviceestablishes a configuration of radio resources (a channel) for use bythe terminal device for communications in accordance with the secondradio access technology and determines if there is any overlap in theradio resources configured for use by the two different radio accesstechnologies, and if so communicates an indication of this to thenetwork infrastructure equipment. For example, the indication of theoverlap may correspond with an indication that the radio resourceswithin the second frequency band configured for use by the terminaldevice for communications with the network infrastructure equipment inaccordance with the first radio access technology comprises aconfiguration which is not supported by the terminal device (at leastfor the time being, i.e. for so long as the overlap situation remains).In response the network infrastructure equipment establishes areplacement configuration of radio resources for communications with theterminal device in accordance with the first radio access technology,wherein the replacement configuration avoids the radio resourcesindicated as being subject to overlap, and transmits an indication ofthe replacement configuration to the terminal device.

Further particular and preferred aspects of the present invention areset out in the accompanying independent and dependent claims. It will beappreciated that features of the dependent claims may be combined withfeatures of the independent claims in combinations other than thoseexplicitly set out in the claims.

Thus, the foregoing discussion discloses and describes merely exemplaryembodiments of the present invention. As will be understood by thoseskilled in the art, the present invention may be embodied in otherspecific forms without departing from the spirit or essentialcharacteristics thereof. Accordingly, the disclosure of the presentinvention is intended to be illustrative, but not limiting of the scopeof the invention, as well as other claims. The disclosure, including anyreadily discernible variants of the teachings herein, define, in part,the scope of the foregoing claim terminology such that no inventivesubject matter is dedicated to the public.

Respective features of the present disclosure are defined by thefollowing numbered paragraphs:

Paragraph 1. A method of operating a terminal device in a wirelesstelecommunications system for communicating with network infrastructureequipment in accordance with a first radio access technology on aprimary cell supporting a primary component carrier on radio resourceswithin a first frequency band and a secondary cell supporting asecondary component carrier on radio resources within a second frequencyband, wherein the terminal device is also operable to use radioresources within the second frequency band for communicating inaccordance with a second radio access technology, wherein the methodcomprises: receiving from the network infrastructure equipment anindication of a configuration of radio resources within the secondfrequency hand for use by the terminal device for communications withthe network infrastructure equipment in accordance with the first radioaccess technology; establishing a configuration of radio resourceswithin the second frequency band for use by the terminal device forcommunications in accordance with the second radio access technology;determining if there is an overlap in the radio resources configured foruse by the terminal device for communications in accordance with thefirst radio access technology and the radio resources configured for useby the terminal device for communications in accordance with the secondradio access technology, and if so, transmitting signaling to thenetwork infrastructure equipment to indicate there is an overlap.

Paragraph 2. The method of any of paragraphs 1 to, further comprisingreceiving from the network infrastructure equipment an indication of anupdated configuration of radio resources within the second frequencyband for use by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology in response to transmitting the signaling to the networkinfrastructure equipment to indicate there is an overlap.

Paragraph 3. The method of paragraph: 2, further comprising determiningif the radio resources associated with the updated configurationincludes radio resources in respect of which the indication of theoverlap is transmitted to the network infrastructure equipment, and ifso, classifying the updated configuration as an invalid configuration oras an unsupported configuration.

Paragraph 4. The method of paragraph 2 or 3, further comprisingdetermining if the radio resources associated with the updatedconfiguration includes radio resources in respect of which theindication of the overlap is transmitted to the network infrastructureequipment, and if so, reverting to a radio resource control, RRC, idlemode in respect of the secondary component carrier.

Paragraph 5. The method of any of paragraphs 1 to 4, further comprisingreceiving from the network infrastructure equipment an indication thatthe configuration of radio resources within the second frequency bandfor use by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology is no longer valid.

Paragraph 6. The method of any of paragraphs 1 to 5, wherein thesignaling to the network infrastructure equipment to indicate there isan overlap is associated with an indication of the radio resources inrespect of which the overlap applies.

Paragraph 7. The method of any of paragraphs 1 to 6, wherein theterminal device is operable to use radio resources within the secondfrequency band for communicating in accordance with a number ofdifferent radio access technologies which are different to the firstradio access technology, and wherein the signaling to the networkinfrastructure equipment to indicate there is an overlap furthercomprises an indication of the second radio access technology in respectof which the overlap has been determined.

Paragraph 8. The method of any of paragraphs 1 to 7, wherein thesignaling transmitted to the network infrastructure equipment toindicate there is an overlap comprises radio resource control, RRC,signaling.

Paragraph 9. The method of any of paragraphs 1 to 8, wherein theterminal device is operable to transmit signaling to the networkinfrastructure equipment to indicate a potential for inter-frequencyinterference arising between different frequencies associated withdifferent radio access technologies supported by the terminal deviceusing an inter-frequency in-device coexistence, IDC, message having apredefined format, and wherein the signaling transmitted to the networkinfrastructure equipment to indicate there is an overlap conforms to theinter-frequency in-device coexistence, IDC, message format.

Paragraph 10. The method of paragraph 9, wherein the signalingtransmitted to the network infrastructure equipment to indicate there isan overlap comprises a message conforming to the predefinedinter-frequency in-device coexistence, IDC, message format with aninformation element selectively set to a value to indicate whether ornot there is an overlap in respect of radio resources identified in themessage.

Paragraph 11. The method of paragraph 10, wherein the informationelement is dedicated to the purpose of indicating whether or not thereis an overlap in respect of radio resources identified in the message.

Paragraph 12. The method of paragraph 10, wherein the informationelement is associated with indicating an aspect of potentialinter-frequency interference arising between different frequenciesassociated with different radio access technologies supported by theterminal device, and in the case of overlap is set to a value which isdifferent from the values used when the information element is used toindicate an aspect of potential inter-frequency interference.

Paragraph 13. The method of paragraph 12, wherein the aspect ofpotential inter-frequency interference with which the informationelement is associated in accordance with the predefined inter-frequencyIOC message format is an indication of the direction of interferencebetween the different radio access technologies.

Paragraph 14. The method of any of paragraphs 1 to 13, wherein thesignaling transmitted to the network infrastructure equipment toindicate there is an overlap comprises a channel quality indicator, CQI,message in respect of the radio resources configured for use by theterminal device for communications in accordance with the first radioaccess technology, wherein a predefined value for the CQI message isselected to indicate there is an overlap in respect of the radioresources to which the CQI message applies.

Paragraph 15. The method of any of paragraphs 1 to 14, wherein theterminal device determines if there is an overlap in radio resourcesaccording to the different configurations in accordance with amonitoring schedule which is initiated in response to receiving from thenetwork infrastructure equipment the indication of the configuration ofradio resources for communications with the network infrastructureequipment in accordance with the first radio access technology.

Paragraph 16. The method of any of paragraphs 1 to 15, furthercomprising: receiving from the network infrastructure equipment at leastone further indication of at least one further configuration of radioresources within the second frequency band for use by the terminaldevice for communications with the network infrastructure equipment inaccordance with the first radio access technology; and determining ifthere is an overlap in the radio resources associated with the at leastone further configuration and the radio resources configured for use bythe terminal device for communications in accordance with the secondradio access technology, and wherein the signaling transmitted to thenetwork infrastructure equipment to indicate there is an overlap furtherindicates the configuration of radio resources for communications withinthe second frequency band in accordance with the first radio accesstechnology to which the overlap applies.

Paragraph 17. The method of any of paragraphs 1 to 16, furthercomprising the terminal device releasing the configuration of radioresources within the second frequency band for use by the terminaldevice for communications with the network infrastructure equipment inaccordance with the first radio access technology in response todetermining there is an overlap in the radio resources configured foruse by the terminal device for communications in accordance with thefirst radio access technology and the radio resources configured for useby the terminal device for communications in accordance with the secondradio access technology.

Paragraph 18. The method of any of paragraphs 1 to 17, wherein thesecond frequency band comprises radio resources which are shared withwireless communication devices that are not part of the wirelesstelecommunications system.

Paragraph 19. The method of any of paragraphs 1 to 18, wherein thesecond radio access technology is a non-cellular telecommunicationsradio access technology.

Paragraph 20. The method of any of paragraphs 1 to 19, wherein thesecond radio access technology is selected from the group comprising: awireless local area network, WLAN, radio access technology; a Bluetoothradio access technology; and a global navigation satellite system, GNSS,radio access technology.

Paragraph 21. A terminal device for use in a wireless telecommunicationssystem for communicating with network infrastructure equipment inaccordance with a first radio access technology on a primary cellsupporting a primary component carrier on radio resources within a firstfrequency band and a secondary cell supporting a secondary componentcarrier on radio resources within a second frequency band, wherein theterminal device is further operable to use radio resources within thesecond frequency band for communicating in accordance with a secondradio access technology, and wherein the terminal device comprises acontroller unit and a transceiver unit configured to operate togetherto: receive from the network infrastructure equipment an indication of aconfiguration of radio resources within the second frequency band foruse by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology; establish a configuration of radio resources within thesecond frequency band for use by the terminal device for communicationsin accordance with the second radio access technology; determine ifthere is an overlap in the radio resources configured for use by theterminal device for communications in accordance with the first radioaccess technology and the radio resources configured for use by theterminal device for communications in accordance with the second radioaccess technology, and if so, transmit signaling to the networkinfrastructure equipment to indicate there is an overlap.

Paragraph 22. Circuitry for a terminal device in a wirelesstelecommunications system for communicating with network infrastructureequipment in accordance with a first radio access technology on aprimary cell supporting a primary component carrier on radio resourceswithin a first frequency band and a secondary cell supporting asecondary component carrier on radio resources within a second frequencyband, wherein the terminal device is further operable to use radioresources within the second frequency band for communicating inaccordance with a second radio access technology, wherein the circuitrycomprises a controller element and a transceiver element configured tooperate together to: receive from the network infrastructure equipmentan indication of a configuration of radio resources within the secondfrequency band for use by the terminal device for communications withthe network infrastructure equipment in accordance with the first radioaccess technology; establish a configuration of radio resources withinthe second frequency hand for use by the terminal device forcommunications in accordance with the second radio access technology;determine if there is an overlap in the radio resources configured foruse by the terminal device for communications in accordance with thefirst radio access technology and the radio resources configured for useby the terminal device for communications in accordance with the secondradio access technology, and if so, transmit signaling to the networkinfrastructure equipment to indicate there is an overlap.

Paragraph 23. A method of operating network infrastructure equipment ina wireless telecommunications system for communicating with a terminaldevice in accordance with a first radio access technology on a primarycell supporting a primary component carrier on radio resources within afirst frequency hand and a secondary cell supporting a secondarycomponent carrier on radio resources within a second frequency band,wherein the terminal device is further operable to use radio resourceswithin the second frequency band for communicating in accordance with asecond radio access technology, wherein the method comprises:establishing a configuration of radio resources within the secondfrequency band for use by the terminal device for communications withthe network infrastructure equipment in accordance with the first radioaccess technology; transmitting to the terminal device an indication ofthe configuration of radio resources within the second frequency bandfor use by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology; receiving from the terminal device an indication of anoverlap in the radio resources configured for use by the terminal devicefor communications in accordance with the first radio access technologyand radio resources which the terminal devoice has established areneeded for use by the terminal device for communications in accordancewith the second radio access technology; establishing a replacementconfiguration of radio resources within the second frequency band foruse by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology, wherein the replacement configuration is selected to avoidradio resources in respect of which the overlap is indicated; andtransmitting to the terminal device an indication of the replacementconfiguration of radio resources within the second frequency band foruse by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology.

Paragraph 24. Network infrastructure equipment for use in a wirelesstelecommunications system for communicating with a terminal device inaccordance with a first radio access technology on a primary cellsupporting a primary component carrier on radio resources within a firstfrequency band and a secondary cell supporting a secondary componentcarrier on radio resources within a second frequency band, wherein theterminal device is further operable to use radio resources within thesecond frequency band for communicating in accordance with a secondradio access technology, and wherein the network infrastructureequipment comprises a controller unit and a transceiver unit configuredto operate together to: establish a configuration of radio resourceswithin the second frequency band for use by the terminal device forcommunications with the network infrastructure equipment in accordancewith the first radio access technology; transmit to the terminal devicean indication of the configuration of radio resources within the secondfrequency band for use by the terminal device for communications withthe network infrastructure equipment in accordance with the first radioaccess technology; receive from the terminal device an indication of anoverlap in the radio resources configured for use by the terminal devicefor communications in accordance with the first radio access technologyand radio resources which the terminal devoice has established areneeded for use by the terminal device for communications in accordancewith the second radio access technology; establish a replacementconfiguration of radio resources within the second frequency band foruse by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology, wherein the replacement configuration is selected to avoidradio resources in respect of which the overlap is indicated; andtransmit to the terminal device an indication of the replacementconfiguration of radio resources within the second frequency band foruse by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology.

Paragraph 25. Circuitry for network infrastructure equipment for use ina wireless telecommunications system for communicating with a terminaldevice in accordance with a first radio access technology on a primarycell supporting a primary component carrier on radio resources within afirst frequency band and a secondary cell supporting a secondarycomponent carrier on radio resources within a second frequency band,wherein the terminal device is further operable to use radio resourceswithin the second frequency band for communicating in accordance With asecond radio access technology, and wherein the circuitry comprises acontroller element and a transceiver element configured to operatetogether to: establish a configuration of radio resources within thesecond frequency band for use by the terminal device for communicationswith the network infrastructure equipment in accordance with the firstradio access technology; transmit to the terminal device an indicationof the configuration of radio resources within the second frequency bandfor use by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology: receive from the terminal device an indication of an overlapin the radio resources configured for use by the terminal device forcommunications in accordance with the first radio access technology andradio resources which the terminal devoice has established are neededfor use by the terminal device for communications in accordance with thesecond radio access technology; establish a replacement configuration ofradio resources within the second frequency band for use by the terminaldevice for communications with the network infrastructure equipment inaccordance with the first radio access technology, wherein thereplacement configuration is selected to avoid radio resources inrespect of which the overlap is indicated; and transmit to the terminaldevice an indication of the replacement configuration of radio resourceswithin the second frequency band for use by the terminal device forcommunications with the network infrastructure equipment in accordancewith the first radio access technology.

REFERENCES

-   [1] Holma H. and Toskala A, “LTE for UMTS OFDMA and SC-FDMA based    radio access”, John Wiley and Sons, 2009-   [2] ETSI TS 136 211 V11.5.0 (2014 Jan.)/3GPP TS 36.211 version    11.5.0 Release 11-   [3] ETSI TS 136 212 V11.4.0 (2014 Jan.)/3GPP TS 36.212 version    11.4.0 Release 11-   [4] ETSI TS 136 213 V11.6.0 (2014 Mar.)/3GPP TS 36.213 version    11.6.0 Release 11-   [5] ETSI TS 136 321 V11.5.0 (2014 Mar.)/3GPP TS 36.321 version    11.5.0 Release 11-   [6] ETSI TS 136 331 V12.2.0 (2014 Jun.)/3GPP TS 36.331 version    12.2.0 Release 12-   [7] ETSI TR 136 816 V11.2.0 (2011 Dec.)/3GPP TR 36.816 version    11.2.0 Release 11-   [8] ETSI TS 136 300 V12.2.0 (2014 Jun.)/3GPP TS 36.300 version    12.2.0 Release 12-   [9] European patent application EP 14171284.4 (Sony Corporation)    filed on 5 Jun. 2014-   [10] European patent application EP 14171285.1 (Sony Corporation)    filed on 5 Jun. 2014

What is claimed is:
 1. Circuitry for a terminal device in a wirelesstelecommunications system for communicating in accordance with a firstradio access technology on a primary cell supporting a primary componentcarrier on radio resources within a first frequency band and a secondarycell supporting a secondary component carrier on radio resources withina second frequency band, wherein the terminal device is configured touse radio resources within the second frequency band for communicatingin accordance with a second radio access technology, wherein thecircuitry is configured to: receive an indication of a configuration ofradio resources within the second frequency band for use by the terminaldevice for communications in accordance with the first radio accesstechnology; establish a configuration of radio resources within thesecond frequency band for use by the terminal device for communicationsin accordance with the second radio access technology; determine ifthere is an overlap in the radio resources configured for use by theterminal device for communications in accordance with the first radioaccess technology and the radio resources configured for use by theterminal device for communications in accordance with the second radioaccess technology, and if so, transmit 1 to the telecommunication systemto indicate a potential for inter-frequency interference arising betweendifferent frequencies associated with different radio accesstechnologies supported by the terminal device; receive an indication ofan updated configuration of radio resources within the second frequencyband for use by the terminal device for communications with thetelecommunication system in accordance with the first radio accesstechnology in response to transmitting the IDC message to thetelecommunication system; and determine if the radio resourcesassociated with the updated configuration includes radio resources inrespect of which the indication of the overlap is transmitted to thetelecommunication system, and if so, classify the updated configurationas an invalid configuration or as an unsupported configuration.
 2. Thecircuitry of claim 1, wherein the circuitry is configured to determineif the radio resources associated with the updated configurationincludes radio resources in respect of which the indication of theoverlap is transmitted to the telecommunication system, and if so,revert to a radio resource control (RRC) idle mode in respect of thesecondary component carrier.
 3. The circuitry of claim 1, wherein thecircuitry is configured to receive an indication that the configurationof radio resources within the second frequency band for use by theterminal device for communications with the telecommunication system inaccordance with the first radio access technology is no longer valid. 4.The circuitry of claim 1, wherein the IDC message to thetelecommunication system is associated with an indication of the radioresources in respect of which the overlap applies.
 5. The circuitry ofclaim 1, wherein the circuitry is configured to use radio resourceswithin the second frequency band for communicating in accordance with anumber of different radio access technologies which are different to thefirst radio access technology, and the IDC message to thetelecommunication system comprises an indication of the second radioaccess technology in respect of which the overlap has been determined.6. The circuitry of claim 1, wherein the IDC message transmitted to thetelecommunication system comprises radio resource control (RRC)signaling.
 7. The circuitry of claim 1, wherein the IDC message conformsto an IDC message format.
 8. The circuitry of claim 5, wherein the IDCmessage transmitted to the telecommunication system comprises a messageconforming to the IDC message format with an information elementselectively set to a value to indicate whether or not there is anoverlap in respect of radio resources identified in the message.
 9. Thecircuitry of claim 8, wherein the information element is dedicated tothe purpose of indicating whether or not there is an overlap in respectof radio resources identified in the message.
 10. The circuitry of claim8, wherein the information element is associated with indicating anaspect of potential inter-frequency interference arising betweendifferent frequencies associated with different radio accesstechnologies supported by the terminal device, and in the case ofoverlap is set to a value which is different from the values used whenthe information element is used to indicate an aspect of potentialinter-frequency interference.
 11. The circuitry of claim 10, wherein theaspect of potential inter-frequency interference with which theinformation element is associated in accordance with the predefinedinter-frequency IDC message format is an indication of the direction ofinterference between the different radio access technologies.
 12. Thecircuitry of claim 1, wherein the terminal device determines if there isan overlap in radio resources according to the different configurationsin accordance with a monitoring schedule which is initiated in responseto receiving the indication of the configuration of radio resources forcommunications with the telecommunication system in accordance with thefirst radio access technology.
 13. The circuitry of claim 1, furtherconfigured to: receive at least one further indication of at least onefurther configuration of radio resources within the second frequencyband for use by the terminal device for communications with thetelecommunication system in accordance with the first radio accesstechnology; and determine if there is an overlap in the radio resourcesassociated with the at least one further configuration and the radioresources configured for use by the terminal device for communicationsin accordance with the second radio access technology, wherein the IDCmessage transmitted to the telecommunication system indicates theconfiguration of radio resources for communications within the secondfrequency band in accordance with the first radio access technology towhich the overlap applies.
 14. The circuitry of claim 1, wherein thecircuitry is configured to release the configuration of radio resourceswithin the second frequency band for use by the terminal device forcommunications with the telecommunication system in accordance with thefirst radio access technology in response to determining there is anoverlap in the radio resources configured for use by the terminal devicefor communications in accordance with the first radio access technologyand the radio resources configured for use by the terminal device forcommunications in accordance with the second radio access technology.15. The circuitry of claim 1, wherein the second frequency bandcomprises radio resources which are shared with wireless communicationdevices that are not part of the wireless telecommunications system. 16.Circuitry for network infrastructure equipment for use in a wirelesstelecommunications system for communicating with a terminal device inaccordance with a first radio access technology on a primary cellsupporting a primary component carrier on radio resources within a firstfrequency band and a secondary cell supporting a secondary componentcarrier on radio resources within a second frequency band, wherein theterminal device is further operable to use radio resources within thesecond frequency band for communicating in accordance with a secondradio access technology, the circuitry configured to: establish aconfiguration of radio resources within the second frequency band foruse by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology; transmit to the terminal device an indication of theconfiguration of radio resources within the second frequency band foruse by the terminal device for communications with the networkinfrastructure equipment in accordance with the first radio accesstechnology; receive from the terminal device an inter-frequencyin-device coexistence (IDC) message indicating of an overlap in theradio resources configured for use by the terminal device forcommunications in accordance with the first radio access technology andradio resources which the terminal device has established are needed foruse by the terminal device for communications in accordance with thesecond radio access technology; establish a replacement configuration ofradio resources within the second frequency band for use by the terminaldevice for communications with the network infrastructure equipment inaccordance with the first radio access technology, wherein thereplacement configuration is selected to avoid radio resources inrespect of which the overlap is indicated; and transmit to the terminaldevice an indication of the replacement configuration of radio resourceswithin the second frequency band for use by the terminal device forcommunications with the network infrastructure equipment in accordancewith the first radio access technology, wherein the terminal device isconfigured to revert to a radio resource control (RRC) idle mode inrespect of the secondary component carrier in a case that it isdetermined that the radio resources associated with the updatedconfiguration includes radio resources in respect of which theindication of overlap is indicated in the IDC message.
 17. Circuitry fora terminal device in a wireless telecommunications system forcommunicating in accordance with a first radio access technology on aprimary cell supporting a primary component carrier on radio resourceswithin a first frequency band and a secondary cell supporting asecondary component carrier on radio resources within a second frequencyband, wherein the terminal device is configured to use radio resourceswithin the second frequency band for communicating in accordance with asecond radio access technology, wherein the circuitry is configured to:receive an indication of a configuration of radio resources within thesecond frequency band for use by the terminal device for communicationsin accordance with the first radio access technology; establish aconfiguration of radio resources within the second frequency band foruse by the terminal device for communications in accordance with thesecond radio access technology; determine if there is an overlap in theradio resources configured for use by the terminal device forcommunications in accordance with the first radio access technology andthe radio resources configured for use by the terminal device forcommunications in accordance with the second radio access technology,and if so, transmit an inter-frequency in-device coexistence (IDC)message to the telecommunication system to indicate a potential forinter-frequency interference arising between different frequenciesassociated with different radio access technologies supported by theterminal device; receive an indication of an updated configuration ofradio resources within the second frequency band for use by the terminaldevice for communications with the telecommunication system inaccordance with the first radio access technology in response totransmitting the IDC message to the telecommunication system; anddetermine if the radio resources associated with the updatedconfiguration includes radio resources in respect of which theindication of the overlap is transmitted to the telecommunicationsystem, and if so, revert to a radio resource control (RRC) idle mode inrespect of the secondary component carrier.